路用热反射涂层工艺性能研究

为研究路用热反射涂层的工艺性能,采用阿累尼乌斯方程建立了黏度与时间、温度的等温流变模型,计算了不同温度和时间下热反射材料的黏度,分析了温度、时间、组成材料对热反射涂层黏滞性和固化特性的影响。结果表明:模型预测值与实测值最大误差为6.7%;热反射涂层的黏滞性随温度的升高而降低,当温度达到40℃以上时,热反射涂层达到凝胶状态,黏度发生突增现象;黏度与时间的关系受温度影响,当固化温度小于50℃时,黏度随时间的延长先降低后增加,固化温度大于50℃时,黏度与时间成正比关系,且热反射涂层黏度与其组成材料密切相关,黏度与稀释剂掺量成反比;气温为20℃和30℃时稀释剂的最佳掺量分别为30%和20%;热反射涂层的固化时间与材料组成和施工温度有关,固化时间随稀释剂掺量的增加而增加,随固化剂掺量的增加而降低;稀释剂掺量为15%时热反射材料的表干时间为39 min,这说明最大施工时间应控制在39 min以内,且热反射涂层的固化时间随温度的升高而降低,温度在30℃以上时,热反射涂层的实干时间显著降低,不黏胎固化时间为145 min。因此,热反射涂层施工时建议气温在30℃以上,喷洒施工时间应控制在40 min以内,同时在不同施工温度下应选择相应的最佳稀释剂和固化剂掺量。

Spray deposition of FeCrNiMn and high carbon steel coatings by thermite reaction

A novel surface cladding technique was developed to prepare the FeCrNiMn alloy and high carbon steel cladding layers,and the microhardness,bonding strength,abrasion wear and corrosion resistance were investigated.The microstructures of the cladding layers were analyzed by using X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive spectrometry(EDS).The results show that the bonding strength between the substrate and the two cladding layers were(432.6±21)and(438.3±12)MPa,respectively.Vickers hardness values of the two cladding layers were HV418.5and HV329.6,respectively.The corrosion current densities of the two coatings were2.926×10–6and6.858×10–6A/cm2after electrochemical corrosion test in3.5%NaCl solution,and the wear rate were1.78×10–7and1.46×10–6mm3/mN after sliding wear test,respectively.This indicates that a well metallurgical bonding between the coating and the substrate was achieved,the abrasion wear and corrosion resistance of both coatings had been greatly improved compared with the substrate.The novel cladding technology is promising for preparing wear-and-corrosion resistant coatings.